Piston-valve.



J. T. WILSON.

PISTON VALVE.

APPLICATION FILED NOV.15, 1912.

1 72,681 Patented Sept. 9, 1918 2 SHEETS-SHEET l.

TNESSES A Home r J. TfWILSON.

PISTON VALVE.

APPLICATION FILED NOV.15, 19i2.

1,072,681. ntfid Sept.9,1913.

2 SHEETS-SHEET 2.

base with ends 14, and a flange 16 with a beveled surface 17. The surfaces of the ends of a packin ring are beveled to engage the beveled sur ace 17 of the joint plate vided at 21 and 22 to permit the expansion and contraction of the ring. Each packing ring joint is preferably located so as to travel over a bridge in the cage and a pin 23 seated in the ring and with its projecting end movably located within an elongated recess 2a in a flange of the follower or spool prevents the circumferential displacement of the ring from its proper position.

The expansible wide ring 5 (see Fi s. 3 and t) has tongues 25 loosely seated within the grooves 10 in the snap rings, beveled edges 26, and spaced circumferential grooves 53? in its outer surface. The adjacent ends of the ring are slightly separated, as shown by Fig. l. Each integral wall ring 6 has beveled surfaces 28, 29, and a flange 30, the flanges of the two wall rings normally being spaced apart the fraction of an inch, as shown. The'expansible wedge ring 7 (see Fig. 2) has beveled edges 31, 32 and its ends are spaced apart, the joint plate 33 being secured-to one end of the ring and lapped beneath the other endt-o form a steam-tight oint.

The top and bottom sections of the packing shown by Fig. 1 clearly illustrate the 7 relative reciprocal locations of the rings, the

top section being taken through the lapped joints of the packing and wedge rings.

The mode of operation is as follows: Live steam, being admitted to the space between the flanges-of the spool, asses to the under surfaces of the entire pacliing by way of the circumferential series of holes 34 and 35 in the spool. The packing rings 4, 4: and'wide ring 5 are expanded by the steam pressure till their exterior surfaces are in contact with the interior surface of the/cage, and the wedge ring 7 expanding forces the wall rings 6, 6 sidewise and apart'against the beveled surfaces of the packing rings and locks and holds them in fixed positions until steam pressure is withdrawn, when the ex: pansible rings slightly contract. .As the exterior surfaces of the packing rings 4., 4 gradually wear away in repeated service, said rings will expand further and further, that is, successively increase their diameters, until the wall rings are moyed toward each other so the flanges 30 come in contact. Further wear the exterior surfaces of the packing rings, inasmuch asthe wall rings I in contact prevent further expansion of the ackin rin s leavesan-o en ace between P g a a the exterior surfaces of the packing rings 1. A piston valve havin and the inner surface of the cage through which live steam blows and indicates thatthe rings are worn to the predetermined limit.

The meansfor limiting the degree of expansion of the packingrings as disclosed obviously consists of the wall rings with the flanges '30 spaced apart the required distance, when the packing rings are new or unworn, and said wall rings are effective in attaining the desired end. However, other means may be employed .for the same purpose, to wit: The ends of the wedge ring (see Fig. 2) may be suitably spaced apartso that when the packing rings expand under wear to the desired limit, forcing the wall rings nearer together, the movementsof said wall rings will contract the wedge ring till its opposite ends come in contact. lVhen the ends of the wedge ring meet the wall rings cannot move further toward each other, and consequently the packing rings are held against further expansion. The end 14 of each joint plate (see Fig. 7) may be provided with a slot 36 and a pin 37 be seated in the ad acent enuof the packing ring with its end rojecting into the slot and so disposed as to limit the dc 'ee of ,expansion of the packing ring. 'T 'e end of each joint plate i l (see Fig. 8) may be provided with a hook 38 and a hooked plate 39 be secured to the under surface of the adjacent end of the packing ring, the engagement of the hooked ends of the plates limiting the expansion of the packing ring.

Other analogous means may be employed in lieu of the foregoing described means for limiting the degrees of expansions of the packing rings without constituting substantial departures in the application of the principle.

The particular construction of the wallrings and their disposition relative to the other rings so that the'trav l of one toward the other, or both toward ea h other, is limited prevents a packing ring from being dis placed, inasmuch as the wall rings lock them within the recess formed between the flanges,

of the spool and follower.

From the foregoing description taken in connection withthe drawings it becomes clear that I have produced a piston valve embodying improvements of. construction and combinations of parts which are elfective in attaining the modes of operation set forth as the objects of the invention.

What I claim is:

a packing comprising a resilient expansi lc packing ring,

means for admitting steam beneath the pack ing ring to expand the same, and means for ..positively limiting the degree'of'expansion .of the said packing ring.

2. A piston valve having a packing comprising two resilient expansible packing & 1,072,581

of expansion of the packing ring when the able a limited distance relative to the joint exterior surface thereof ha s beenwornto a plate, for the purpose specified.

predetermined amount. In testimony whereof I afiix 1.8. An expansible packing ring having a. ture joint plate secured to one end and the other .7 my signs.- in presence of two witnesses.

- JOHN T. WILSON} end provided with means located-at the-Q? Witnesses! under surface thereof for connecting said AILEN J; FRANTZ, W.. B.- HARLAN.

end to the joint plate, said means being mow 

